So much air blowing in the pilot on DV-35-2SG heater won't stay lit

It sounds like you have a direct vent heater so you have to take off a pilot access cover to light the pilot. So what happens is the draft coming out of the cover is blowing out the match before you get it in the hole. The trick is to get the match or lighter in the hole quickly as possible so the pressure inside the heater will equalize and the match will stay lit. Then you should be able to lite it. Get it inside the hole fast and it will work. Don't forget to put the cover back over the pilot access or the draft may cause the pilot to go back out.

I'm having the same issue as the above user with Jandy Lite 2 (which from what I can tell stands for the number of times that you can get this POS to work annually)!
The unit LIGHTS OFF, but WON'T STAY LIT! Igniter engages, gas valve opens, unit lights, burns for 10 seconds, and flames out. Error code FL 2, after third attempt, already replaced the flame sensor....

Thermostat flame sensor. Do you see a little rod next to the pilot? That is what tells the main gas valve that the pilot is lit and it is safe to give gas. Easy swap, and you can usually just pick up a generic one.

Gas water heaters don't have elements, so I am confused about what type water heater you have..
Look on the side of tank for the label.
Find the brand, and type. Does it show BTUs? Or does it show wattage?
Then re-post question with this information, for best possible answer.
Also post question on Tank forum.
http://www.thetankatwaterheaterrescue.com/forums/forum3/

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Make sure thermocouple tip is seated inside the burner flame.
Make sure thermocouple is not overtightened. Finger-tight + 1/4 turn.
If the pilot lights, then ECO energy cut off is not tripped, but gas control valve might be bad.
Check color of pilot flame: it should be strong and clear blue.
If pilot flame is weak, or color of flame is yellow-orange: Clean pilot orifice and burner and combustion parts on yearly basis.
Clean air intake screen if applicable.
Increase air supply to water heater. Open a window and see what happens.
Check for adequate draft going up chimney using match under vent hood to see if smoke drafts immediately upwards.
Bleed air out of gas line.
Check gas pressure.

Open following links for troubleshoot resources:
http://waterheatertimer.org/pdf/Pilot-light-will-not-stay-lit.pdf
http://waterheatertimer.org/pdf/Pilot-outage-troubleshooting.pdf
http://waterheatertimer.org/pdf/Vent-spillage-test-atmospheric-gas-water-heater.pdf
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

The pilot flame must touch (burn) the tip oqef the t-couple to hold the magnet in the gas value open.make sure the pilot orifice (hole) is clear.the pilot pressure (in the tube) is factory set full open & can only be adjusted down (less). Also check the gas **** didn't get closed or turned half way.? Assuming its not the t-couple. If all is good & it still won't stay on. Replace the gas value.!

If pilot lights and flame is robust and clear blue, and pilot goes out later, then some suspects can be excluded: air in gas line, low gas pressure, thermocouple is overtightened (finger-tight + 1/4 turn), thermocouple not positioned correctly in the flame, dirty pilot tube.
If flame is yellowish and small: then clean pilot tube and combustion parts.
http://waterheatertimer.org/How-to-install-gas-water-heater.html#clean
Remaining suspects can include: air in gas line, low gas pressure, bad gas control valve, tight house so household vent fans pull air down water heater vent that blows out pilot, hot attic with inadequate ventilation, water dripping down vent.

Open following links to read troubleshoot resources.
http://waterheatertimer.org/pdf/Pilot-light-will-not-stay-lit.pdf
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

sounds like your thermacouplar is going out and needs replaced. Sometimes these will act like they are working fine , but when the pilot stays on for awhile and later goes out it is a sure sign that it is bad

The thermocoupler is no good. It's that bulb sitting in the pilot flame. when it goes out it shuts everything doen in the main valve. It has to be kept hot by the pilot, that's how it know whether or not it is safe to open the main .